Sentry Industries 5000 User Manual

 

Although the Sentry system is designed and constructed 
for installation and operation in industrial applications 
including "hostile" environments, caution should be taken 
to insure that the installation is made in compliance with 
this instruction manual and that certain procedures and 
conditions are avoided.  This chapter discusses the 
necessary cautions.  Read the entire chapter prior to 
installation of the equipment. 

The controller should be installed in a location which is 
safely accessible during a gas alarm. 

Avoid installing the controller where it will be 
unnecessarily exposed to wind, dust, shock or vibration or 
direct sun.  Observe temperature range limitations. 

Adhere to standard electrical installation procedures.  The 
chassis ground on the controller must be connected to 
earth ground.  

While the digital communication method used between 
the controller and modules will greatly reduce problems 
associated with electromagnetic and radio frequency 
interference the manufacturer recommends that extra 
caution be taken where the installation is near any sources 
of these interferences: 

• 

Avoid running sensor module cable close to high 
power cables, radio transmission lines, or cables 
subject to pulses of high current.  

• 

Avoid running cables near large electric motors or 
generators. 

• 

When the risk of interference is present use shielded 
cables.  In conduit installations the shield should be 
connected to the conduit. In cable applications the 
shield should be connected to the cable connector. 

• 

All splices must be via either a lug and terminal 
system or soldered.  Improperly spliced cable can 
result in corrosion, resistance changes and system 
errors. 

Avoid installing sensor modules where they will be 
unnecessarily exposed to wind, dust, water (esp. direct 
hose down), shock, or vibration.  Observe temperature 
range limitations. 

Sensors may be adversely affected by prolonged exposure 
to certain materials.  Loss of sensitivity, or corrosion, may 
be gradual if such materials are present in low 
concentrations.  These materials include: Halides 
(compounds containing chlorine, fluorine, bromine, 
iodine), silicones, acid vapors, caustic liquids or mists. 

Care has been taken by the manufacturer to ship your 
modules in protective packaging to avoid contamination 
prior to installation.  It is recommended that the sensors 
remain protected during installation and that the covering 
be removed immediately prior to system start-up. 

During normal use the sensor is protected from dirt and 
oil contamination by a sintered metal cover.  If this cover 
becomes clogged, the response of the sensor will be 
reduced.  Protect the sensor from contamination by careful 
placement, or by use of rain and dust shields. 

Sensor modules must not be painted.  Paint may contain 
compounds which will contaminate the sensor.  Paint will 
cause clogging of the sintered metal cover and will cause 
difficulties during attachment of the calibration head or 
other maintenance activity.  It is recommended that the 
module be tagged 

. 

When sensors are replaced the thread must be Teflon 
taped to avoid metal to metal binding which will damage 
the housing threads.  

Catalytic type combustible gas sensors may be poisoned 
by exposure to silicones.  Sierra Monitor Corporation 
supplies resistant sensors, but care should be taken to 
avoid exposure to silicones.  No Silicone caulking (RTV) 
should be used near the sensors.  No other silicone based 
compounds should be used near the sensors unless they 
are fully protected during the entire cure cycle.  If the 
sensors will be exposed to silicone during normal 
operation the manufacturer's sensor warranty is void.